BRCA testing:Who should test, and how it works

BRCA testing is a genetic test—usually performed on a blood or saliva sample—that looks for inherited changes in the BRCA1 and BRCA2 genes linked to higher breast, ovarian, pancreatic, and prostate cancer risk.

It does not diagnose cancer. It helps estimate inherited susceptibility and may inform risk management for the person tested and their relatives. For gene function, inheritance, and cancer-risk ranges, start with what BRCA1 and BRCA2 do. ^{[11, 15, 16]}

Consider discussing genetic risk assessment with a clinician or genetic counselor if:

• A blood relative has a known pathogenic BRCA1 or BRCA2 variant.
• You or a close relative had breast cancer at age 50 or younger, ovarian cancer, male breast cancer, pancreatic cancer, or metastatic or high-risk prostate cancer.
• You have Ashkenazi Jewish ancestry, especially alongside a relevant cancer history.
• You have a cancer diagnosis for which inherited genetic information could inform treatment or help relatives.
• A BRCA change appeared on a tumor test and you need to learn whether it is inherited.

These examples are not a complete eligibility checklist. Review cancer history on both sides of your family, the age at each diagnosis, and any available genetic reports. When possible, testing a family member who has had cancer first can make later results easier to interpret. ^{[1, 2]}

This is a conversation aid, not an eligibility decision. Criteria can change, and a genetics professional may consider details not captured here.

1. 01

   Review the family pattern

   A clinician or genetic counselor reviews cancer types, ages at diagnosis, ancestry, and both sides of the family. Counseling should cover possible results, limitations, privacy, and implications for relatives. ^{[9, 10, 12, 15]}

2. 02

   Test the most informative relative when possible

   Testing a relative who has had a relevant cancer first is usually more informative than starting with an unaffected relative. If a familial variant is already known, the laboratory can test directly for it. ^{[11, 12, 15, 16]}

3. 03

   Choose the clinical test

   A blood or saliva sample may be tested for BRCA1/2 alone, a known family variant, or a multigene hereditary-cancer panel. A panel can include genes such as PALB2, TP53, PTEN, CHEK2, and ATM when the family pattern is not explained by BRCA alone. ^{[8, 12, 15, 16]}

4. 04

   Interpret the report in context

   Results commonly take several weeks or longer. Timing varies by laboratory, test scope, insurance steps, and whether clarification or confirmation is needed. ^[12]

Start with the clinical question—not the amount of data a test can produce. The most direct test is often the most useful one.

BRCA1 and BRCA2 are not the only genes that can matter for inherited cancer risk. Depending on family history, a clinician may also consider genes such as PALB2, ATM, CHEK2, or genes associated with Lynch syndrome. The National Cancer Institute describes multigene panels as one testing approach when a family’s causative variant is unknown. If the exact variant is already known, a targeted family test may be the most direct first step. ^{[2, 3]}

Your two inherited copies of the genome together contain roughly 6 billion DNA letters. WGS sequences across that genome instead of restricting data collection to a short list of preselected genes. This creates a broader genomic record that can potentially be revisited as evidence and interpretation improve. ^{[4, 5]}

Its usefulness depends on the question you are trying to answer and how the resulting data are interpreted alongside your personal and family history. ^{[2, 5]}

Positive

A pathogenic or likely pathogenic variant means increased risk of certain cancers. It does not mean you currently have cancer or will inevitably develop it.

Negative

A negative result is especially informative when the exact familial variant was tested and not found. Without a known familial variant, it does not erase a concerning family history.

Uncertain

A variant of uncertain significance is a change whose effect is not established. It should not, on its own, drive risk-reducing surgery or other major care decisions. ^[1]

A confirmed pathogenic BRCA finding can lead to a personalized discussion of earlier or more intensive breast screening, risk-reducing measures, and prostate or pancreatic screening in appropriate circumstances. Recommendations depend on the gene, age, sex, and family history. There is currently no established effective ovarian cancer screening test, so ovarian risk reduction needs a separate clinical discussion. ^[1]

GRAIL recommends the Galleri test for adults at elevated cancer risk, such as those age 50 or older. Galleri does not detect every cancer. A result of “No Cancer Signal Detected” cannot rule cancer out, and a positive signal requires diagnostic follow-up. ^[7]

For someone with a pathogenic BRCA variant, Galleri does not replace recommended breast imaging or other gene-specific and routine cancer screening. Ask your clinician whether it has a useful supplemental role in your plan. ^[7]

1. 01

   If a relative has a known variant: Bring the relative’s laboratory report to a genetics professional and ask about targeted testing.

2. 02

   If you want to understand broader inherited risk: Explore HLI’s $599 whole genome sequencing and ask how the results will be interpreted in light of your family history.

3. 03

   If you already carry a pathogenic BRCA variant: Review your screening and risk-reduction plan with your clinician. Discuss Galleri (opens in a new tab) only as a possible addition to that plan.